Test head manipulator technology is used in the semiconductor testing industry to hold and position test heads for testing semiconductor products (IC dies and computer chips). The manipulator also repositions the test head for service and maintenance. In the semiconductor testing industry, test floor space is at a premium. Existing methods of test head manipulation generally use a single manipulator that is always attached to the test head for each test cell with additional service space for the maintenance of equipment and other operations. As some semiconductor test companies increase the number of test cells, the area generally reserved for the manipulator and service access is removed, resulting in little to no space to perform traditional test head manipulation and services.
An example of a manipulator is disclosed in U.S. Pat. No. 7,312,604 issued to Paul Trudeau, et al. In this reference, a manipulator is described for positioning a test head relative to a prober or other reference. The manipulator has a frame, a linkage coupled to the frame and including first and second links having freedom of rotation about respective pivots and a third link coupled to the first and second links such that the third link has translational and rotational degrees of freedom of movement, and an adaptor coupled to the third link and configured to attach to a test head.
Another example of a manipulator is disclosed in U.S. Pat. No. 5,931,048 issued to Alexander H. Slocum, et al. In this reference, a manipulator for a test head is connected to automatic test equipment through a heavy, inflexible cable. The manipulator includes a telescoping column assembly to which is mounted a vertical member. A cradle holding the test head is mounted to the vertical member. The cable is clamped at the vertical member to reduce the amount of force exerted by the cable on the test head. The cradle includes movable members to allow fine positioning of the test head, while maintaining the test head isolated from cable force. Coarse motion of the test head may be made by moving portions of the manipulator on the opposite side of the cable clamp from the test head. Precise positioning of the test head relative to a handling device is accomplished through a positioning mechanism at the interface between the test head and the handling device. To allow the positioning mechanism to operate, the manipulator has compliance which allows the test head to be forced into position by the positioning mechanism. Both of these references are herein incorporated by reference for all that they contain.